Entropion Lower Eyelid Reconstruction

Lower lid entropion is a common condition in elderly individuals; the prevalence increases steadily with age.[1] Entropion is an inversion of the eyelid (ie, inward turning of the eyelid margin) toward the globe. According to its anatomic features, the condition is classified as involutional, cicatricial, or congenital. Choice of surgical approach is directed by the underlying etiologic factor(s).

See the image below.

Entropion occurs most often in the lower eyelid. The condition may be mild or severe, and it usually involves the entire eyelid margin.

Frequency

Entropion is more frequent in women then in men. This disparity may be related to the relatively smaller (on average) tarsal plates of women.

Entropion is most commonly observed as an involutional change associated with horizontal laxity of the involved eyelid.

Congenital entropion

Congenital entropion is rare and usually involves the lower lid. The cause is often a vertical deficiency of the posterior lamella.

Involutional entropion

Involutional entropion is the most common form of entropion. For many years, physicians have wondered why some patients develop ectropion and others entropion, when both conditions seem to share identical etiologic factors. Bashour and Harvey recently solved this conundrum.[2]

They found that patients with involutional entropion have smaller-than-average tarsal plates for their ages. Involutional entropion results from the vector mechanical effect of an atrophied or smaller-than-average (partially or fully disinserted) tarsal plate being overcome by the normal or increased tone of the preseptal/pretarsal orbicularis muscle. Patients with anophthalmic socket may have involutional entropion because of enophthalmic socket.

Patients with involutional ectropion have larger-than-average tarsal plates for their ages. Involutional ectropion results from normal or larger-than-normal tarsal plate vector forces mechanically overcoming the normal or decreased tone of the preseptal/pretarsal orbicularis muscle in combination with medial/lateral canthal tendon laxity.

Cicatricial entropion

Cicatricial entropion results from scarring of the posterior lamella by conditions such as alkali burns, trauma, blepharoplasty, and ocular cicatricial pemphigoid. Entropion is rare in individuals younger than 60 years, and one of the most common causes of cicatricial entropion in the industrialized world is Stevens-Johnson syndrome.

Spastic entropion

Spastic entropion may occur with severe blepharospasm or hemifacial spasm.

Causal factors leading to entropion include horizontal laxity of the eyelid (universal), dehiscence of the lower eyelid retractors, vertical shortening of the posterior lamella of the eyelid, and spasm or overactivity of the orbicularis oculi muscle.

A study by Michels et al indicated that risk factors for either entropion or ectropion of the eyelid include dehiscence of the eyelid retractors, presence of a "white line," orbital fat prolapse in the cul-de-sac, decreased excursion and increased distraction of the lower eyelid, and increased laxity of the eyelid (as measured by the snapback test). Increased eyelid crease height and reduced lateral canthal excursion were also found to increase the risk of entropion.[3]

Presentation is usually because of epiphora, ocular irritation, or cosmesis.

Indications for surgery to correct entropion include epiphora, ocular irritation, cosmesis, and corneal damage.

Thorough knowledge of eyelid anatomy is essential to appreciate the etiology and surgical intervention of lower eyelid abnormalities. The eyelid can be conceptualized to consist of an anterior and posterior lamella.

The anterior lamella consists of the skin and orbicularis muscle. The thin, delicate skin of the eyelid lacks dermal-like connective tissue and pilosebaceous apparatus that would reduce eyelid mobility. The orbicularis muscle is categorized as orbital or palpebral portions, based on adjacent anatomic structures. The orbital orbicularis muscle overlies the orbital rim. The palpebral orbicularis muscle is classified further as preseptal or pretarsal, based on the proximity of orbital septum or tarsus, respectively. At the eyelid margin, a strip of orbicularis muscle is associated directly with the eyelashes. This strip is the Riolan muscle.

The posterior lamella consists of the eyelid retractor, tarsus, and conjunctiva. The lower eyelid is analogous to the upper eyelid, with the eyelid retractor system as the main variation. The upper eyelid has a distinct eyelid retractor (ie, levator muscle) to enhance upper eyelid mobility. The lower eyelid does not have a specialized eyelid retractor. The lower eyelid retractor system originates as a fascia extension of the inferior rectus muscle (capsulopalpebral head). This fascial system splits to encapsulate the inferior oblique muscle and then reunites to form a dense fibrous sheet (capsulopalpebral fascia) to insert onto the inferior tarsal border.

The inferior tarsal muscle is a smooth muscle analogous to the superior tarsal muscle (Müller muscle) of the upper eyelid. This muscle originates in the inferior fornical area and extends toward the inferior tarsal border but does not insert on the tarsal border as does its counterpart in the upper eyelid. The inferior tarsal muscle provides sympathetic innervation to the lower eyelid, and interruption of its innervation results in a slightly elevated position of the lower eyelid margin, as observed in Horner syndrome. Otherwise, the inferior tarsal muscle has little pathologic significance. The tarsus provides the primary support or foundation for the eyelids. Although degeneration of the tarsus may promote eyelid laxity, the principle focus of weakness of the eyelids is at the lateral and medial canthal tendons.

The medial canthal tendon has a prominent anterior component firmly connecting the medial canthal angle to the maxillary process of the frontal bone. The posterior limb of the medial canthal tendon provides deep support to the posterior lacrimal crest. The superior branch of the medial canthal tendon also supports the canthal angle. The lateral canthal tendon has contributions from the lateral aspects of the tarsus and the preseptal and pretarsal orbicularis muscle; these insert on the inner aspect of the lateral orbital rim at the Whitnall (lateral orbital) tubercle. The posterior deep insertion of the lateral canthal tendon allows the lateral aspect of the eyelids to approximate the globe.

Surgery to correct entropion is contraindicated in patients who are unable to tolerate the procedure.

See the list below:

• Snap-back test

  • Perform this test by pulling the lower lid away and down from the globe for several seconds. If the lid resumes position, note the time required for the lid to return to its original position without the patient blinking.

  • The snap-back test provides a good idea of relative lower lid laxity. Lids with normal laxity immediately spring back to original position; the longer this takes, the more laxity is present.

  • Assign grades on a scale from 0-4 (0 = normal laxity, 4 = severe laxity).

• Medial canthal laxity test

  • Perform this test by pulling the lower lid laterally from the medial canthus. Measure displacement of the medial punctum. Greater distance equates to more laxity. Normal displacement ranges from only 0-1 mm.

  • Assign grades on a scale from 0-4 (0 = normal laxity, 4 = severe laxity).

• Lateral canthal laxity test

  • Perform this test by pulling the lower lid medially from the lateral canthus. Measure displacement of the lateral canthal corner. Greater distance equates to more laxity. Normal displacement ranges from only 0-2 mm.

  • Assign grades on a scale from 0-4 (0 = normal laxity, 4 = severe laxity).

• Schirmer test

  • Because entropion is only one of several differential diagnoses of epiphora, having a measure of the degree of eye dryness is important. The Schirmer test is used to assess tear production and provides such a measure.[4]

  • Tiny filter paper tabs are inserted in the lower lids and removed after a few minutes. The dampened area is measured in millimeters.

• Fluorescein cornea test

  • This test is essential when looking for signs of corneal damage.

  • It can detect damage from lashes or lid skin rubbing on the cornea.

• Lacrimal system irrigation

  • Check for lacrimal system blockage.

  • If the system is blocked, a dacryocystorhinostomy (alone or in combination with an entropion procedure) would possibly be better than treating the entropion alone.

• Slit-lamp examination

  • This examination is especially good for checking corneal status.

  • The test also checks for evidence of dryness.

• Presence or absence of Bell phenomenon test

  • Instruct patient to attempt eye closure while the examiner holds lids open.

  • If eyes move up, the test indicates a positive result for Bell phenomenon.

• Orbicularis muscular tone check

  • Check orbicularis muscular tone if the patient exhibits evidence of ocular muscle spasm caused by postoperative irritation, essential blepharospasm, or hemifacial spasm.

  • Ask the patient to squeeze eyes shut. Note how much worse the entropion is immediately after opening.

  • Grade the strength from 0-4 (0 = no paralysis, 1 = weak, 2 = normal, 3 = overactive, 4 = spastic).

If surgical therapy is unwarranted or impossible, patients with lower lid entropion should be treated medically. Symptomatic therapy can be achieved using artificial tear ointment or drops. Moisture shields are also helpful. Additionally, the lower lid can be taped down slightly, everting the lid and lashes from the eye using specially designed or normal skin tape.

For temporary spastic entropion (eg, from postoperative ocular surgery), botulinum toxin (BOTOX®) injections to the lower lid can be considered. The author usually administers 3 injections of 5 units BOTOX® laterally, centrally, and medially. Effects usually start in 2 days and last 3-6 months. If the inciting event disappears, BOTOX® injections can be a permanent cure.

The same BOTOX® therapy can also be a useful adjunct in reoperations or surgical treatments, especially in patients in whom orbicularis tone is 3-4 or higher.

The correct surgical treatment of entropion depends on etiology.[5] Horizontal lid laxity is often observed with entropion and can usually be corrected with a lateral tarsal strip procedure.[6, 7]

Entropion often requires reinsertion of lower lid retractors. Augmentation of posterior lamellae (along with excision of any cicatrix) is required for cicatricial entropion and can be helpful in reoperations after simpler procedures have failed.

The author recommends using a corneal protector during oculoplastic procedures. The surgeon must be wary of the remote possibility of flash burns whenever oxygen is on the surgical field. Failure to use a corneal protector may transform an elective lid repair into a much more complicated problem.

Patient comfort should be ensured during surgery. Since most cases of ectropion involve the lower lid, supplemental infraorbital nerve block is a useful adjunct to direct injection and subconjunctival injection.

Suture repair - Everting sutures

The author does not advocate this temporary repair method. Double-armed chromic sutures are passed through the fornix near the orbital rim, emerging at the skin surface just under the lash line. Even though this procedure often is not useful alone, it can be a useful adjunct to another procedure (eg, lateral tarsal strip).

A study by Jang et al found that of 69 patients with involutional entropion who were treated with Quickert sutures, 34 of them (49.3%) experienced a recurrence within a 2-year follow-up period.[8]

The lower lid diamond

This is a useful technique (described here[9] ) with a higher success rate than everting sutures and is particularly suitable for patients for whom rapid surgery is needed or a lateral canthotomy is best avoided.

Congenital entropion

The surgeon should try to differentiate this extremely rare condition from epiblepharon, which is much more common. Epiblepharon is corrected easily with an elliptical orbicularis-skin excision and interrupted 6-0 gut skin closure.

Lateral tarsal strip

Horizontal lid laxity is a component of most entropion cases, especially involutional entropion. Whenever feasible, the author prefers a lateral canthal-tightening procedure. Surgery at the lateral canthus avoids the possibility of lid notching with noncanthal procedures and decreases the risk of trichiasis. The most common variation of lateral canthal tightening is the lateral tarsal strip procedure.[10]

The lateral canthus can be clamped prior to canthotomy; then perform inferior cantholysis with Westcott scissors. The lower lid should then be freely mobile. Excess lid skin can be draped over the lateral canthus. Excise an appropriate triangle of full-thickness lid.

Approximately 3 mm of the lateral lid then is split at the gray line with sharp Westcott scissors or a No-15 blade. Trim away meibomian orifices of the lateral strip. Scrape the lateral conjunctiva to avoid epithelial inclusion cysts.

To secure the lateral strip of tarsus to the periosteum, 2 sutures (or a single horizontal mattress suture) can be placed approximately 4-5 mm posterior to the lateral orbital rim near the Whitnall tubercle (at or above the level of the inferior pupil). Suitable sutures with small semicircular needles include 5-0 Vicryl on a P2 needle or 4-0 Prolene on a PS-5 needle. Retracting the upper lid supertemporally and placing a cotton-tipped applicator at the lateral canthus to palpate the inner lateral orbital rim may help.

Before tying the suture, remove the corneal shield. The orbicularis layer can be closed with 6-0 Vicryl, and the skin can be closed with 6-0 plain gut. A stitch through the lateral-most gray line of the upper and lower lateral lid helps keep the lateral canthus sharp.

If the patient requires topical drops (eg, glaucoma therapy) postoperatively, do not retract the lower lid for the first month during drop instillation.

Patients often complain of prolonged discomfort at the lateral canthus following this procedure.

Severe entropion with retractor disinsertion

This complete inversion of the lower lid occurs when the capsulopalpebral fascia is disinserted from the inferior tarsal border. In addition to horizontal lid tightening, reinsert the retractors (ideally from a skin approach).

A double-armed 5-0 chromic suture can be used to reattach the capsulopalpebral fascia to the inferior tarsus in running fashion.

Spastic entropion

A tarsal strip procedure often is helpful. Only 0-2 mm of the lateral lower lid may have to be excised. In patients with extreme spastic ectropion, surgery can be augmented with preoperative or postoperative BOTOX® injections.

Cicatricial entropion

An enhanced tarsal strip (ie, tarsal strip with a posterior lamellas spacer graft) may help correct some degree of cicatricial ectropion. Spacer grafts may be obtained from the upper lid (tarsus), roof of the mouth (hard palate), nasal septal cartilage, buccal mucosa, or banked sclera. A superior traction suture decreases risk of recurrent cicatrix postoperatively. All these areas can and have been used; the best area is likely the one that is most similar to the existing tissue, ie, the tarsoconjunctival plate from the upper lid.[11]

For lid sutures, the author prefers an antibiotic steroid combination (eg, Maxitrol [neomycin, polymyxin, bacitracin]) administered three times per day. Applying cold compresses to the eyelids every 15 minutes (as tolerated) while awake decreases bruising and swelling. Frozen peas in a plastic bag are a useful alternative to traditional cloth compresses.

The author generally does not prescribe narcotics postoperatively. The patient is asked to use oral acetaminophen 325-650 mg every 4 hours as needed. Patients are asked to avoid aspirin-containing products.

Patients are usually reviewed on the first postoperative day, then 5-7 days later for suture removal.

Complications are primarily related to corneal damage and can involve corneal breakdown, ulcer formation, epiphora, and pain. Surgical complications may include bleeding, hematoma, infection, wound dehiscence, pain, and poor positioning of the tarsal strip.

Entropion surgery often has a poorer outcome than ectropion surgery and more recurrences. Frequency of surgical failure can be greatly reduced by carefully looking at the etiology of the entropion. Augmentation with BOTOX® for overacting orbicularis, augmentation with a spacer graft for patients with short posterior lamellae, and reinsertion of inferior retractors all can be helpful, either singly or in combination.[12, 13]